The invention relates to a latch device for securing and/or guiding at least one cargo item.
In the cargo hold of an aircraft, in particular of a wide-body aircraft, cargo items (e.g. containers or pallets, ULD: unit load devices) are usually moved by means of roller conveyors. Fixing rails (e.g. profile rails) which are mounted on the aircraft's cargo loading deck are used to accommodate functional elements. Such functional elements may be latch devices/fastening devices for at least partial securing of cargo items. The latch devices may also be integrated directly in the cargo hold.
Corresponding latch devices are used not only for securing the cargo items in their end position but also for guiding the cargo items in a specified direction. The cargo items are frequently driven by means of freight conveying devices (PDU: power drive units) with the result that it is necessary to specify a defined direction by using the latch devices. Cargo holds are frequently divided by means of a plurality of latch devices into a plurality of cargo loading paths which are adapted to the size of the cargo items.
A faulty cargo loading system, whether this is due to incorrect operation or normal wear, can lead to substantial costs since it is very expensive to maintain a wide-body aircraft. Every minute that a wide-body aircraft spends on the ground costs the operator money.
Furthermore, it must be considered that weight plays a crucial role when transporting cargo by aircraft. Attempts are therefore made to minimise the dead weight of the aircraft, in particular of the cargo loading system. Attempts are made to provide a plurality of configurations of the cargo loading deck with as few functional elements (e.g. latch devices) as possible.
Furthermore, the loading and unloading of relevant wide-body aircraft should also be carried out as quickly as possible. Loading and unloading is preferably either partially automated or fully automated. The functional elements guide the cargo items during loading and unloading, e.g. by specifying cargo loading paths. When conveying the cargo items into the interior of the cargo hold, it is extremely problematic if the cargo items become jammed inside a cargo loading path. In these cases, this may result in damage to the cargo loading system. In the most favourable case, a manual intervention is necessary in order to re-align the cargo items in an appropriate manner. This intervention costs valuable time.
U.S. Pat. No. 5,011,348 discloses a fastening device which is installed in the centre of a cargo loading deck along the aircraft's longitudinal direction and which serves there as a guide. This central bar (centre guide) has two locking claws, attached to each of which is a locking lug, said locking lugs pointing in opposing directions. The locking lugs are designed to grip partial sections of the cargo items, to secure them in the aircraft's transverse direction (Y-axis) and to hold them firmly in such a manner that the cargo items cannot be lifted out of the guide. The locking claws are articulatedly supported on a frame such that they can be folded away longitudinally when they are passed over by a cargo item. The mechanism associated with this is very complex and costly. The whole construction of the latch device disclosed in U.S. Pat. No. 5,011,348 is very large and requires sufficient space. In addition, the latch device has a heavy and complicated construction such that numerous elements can fall out in the harsh environment in which it is used.
In addition, a foldable latch device for securing and/or guiding at least one cargo item is disclosed in DE 10 2010 017 535 A1. This can be moved in the aircraft's transverse direction to adjust the width of the cargo conveying paths to the cargo items. The latch device has two locking lugs each pointing in opposing directions which can secure the cargo items in two adjacent parallel cargo conveying paths. This latch device is relatively bulky which means that adequate space must be provided for it in the cargo loading deck. The latch device cannot be mounted in existing profile rails. Moreover, the latch device of DE 10 2010 017 535 A1 is not very suitable for guiding cargo items while they are being conveyed in a cargo conveying path, which means that the cargo item may turn sideways within the cargo conveying path. The result of this is that the latch device folds away out of its restraining position into its inoperative position. In the inoperative position, it can easily be passed over by the cargo item which, although this prevents damage to the latch device, nevertheless leads to a delay in the loading process.
U.S. Pat. No. 6,270,300 B1 discloses a further latch device which is provided with pivotable lugs which requires a minimum width of 2 inches between two cargo items or ULDs. If this latch device were to be constructed with rigid lugs to achieve a smaller minimum width, the result when the cargo item is pivoted would (frequently) be jamming as it would drag with it the edge of a cargo item passing alongside. It is essential to prevent such stopping of a moving cargo item (ULD).
Based upon this prior art, it is an object of the present invention to provide an improved latch device for securing and/or guiding at least one cargo item. In particular, the intention is to provide a latch device which ensures safe guidance of the cargo items, which is preferably pivotable into a non-operative position/inoperative position and/or can be mounted in existing profile rails.
In particular, the object is achieved by a latch device for securing and/or guiding at least one cargo item on a cargo deck/cargo loading deck, wherein the latch device comprises:
a sliding carriage extending longitudinally;
a bearing in which the sliding guide carriage is movably supported in such a way that the sliding guide carriage is pivotable out of a restraining position into an inoperative position;
at least one releasing device which is attached to the latch device by way of at least one articulation in such a way that the releasing device can be brought out of a blocking position into a releasing position, wherein in the blocking position the releasing device acts on the sliding guide carriage in such a manner that said carriage is locked in the restraining position, wherein the releasing device has at least one releasing device ramp section which is designed and arranged in such a manner that a cargo item approaching longitudinally pivots the releasing device out of the blocking position into the releasing position.
One advantage of the invention is that the latch device can be configured very compactly. It is possible to mount this latch device in or within a relatively narrow profile rail, which also has, for example, roller drive units, passive rollers and/or latches which secure the cargo items in the aircraft's longitudinal or transverse direction. The separate configuration of the releasing device prevents unintentional lowering of the sliding guide carriage when cargo items approach the sliding guide carriage laterally or are in contact with it. When approaching the latch device longitudinally, however, the sliding guide carriage is released with the result that it can be pivoted out of the restraining position into the inoperative position or it moves aside automatically. The ramp section enables automatic triggering of the releasing device such that it is pivoted out of the blocking position into the releasing position by an approaching cargo item. In the blocking position, the releasing device blocks the sliding guide carriage such that it remains firmly in the restraining position. In the releasing position of the releasing device, it is possible to switch between restraining position and inoperative position of the sliding guide carriage. In the restraining position of the sliding guide carriage, said carriage can hold onto and guide cargo items while in the inoperative position the sliding guide carriage can be passed over by cargo items.
Using the latch device according to the invention, it is possible to equip a cargo loading deck in such a way that cargo items with different dimensions can be transported easily and securely. It is relatively easy to convert the cargo loading deck. In addition, the pivotability of the sliding guide carriage ensures that even with incorrect handling the latch device and/or cargo items are not damaged, as the sliding guide carriage simply descends—along the longitudinal direction—as long as it is approached laterally.
The latch device's transverse direction is preferably defined such that it runs perpendicular to the latch device's longitudinal direction. For pivoting the releasing device between the blocking position and the releasing position, however, it is not necessary for the cargo item to travel towards the releasing device ramp section from exactly the longitudinal direction. This releasing device ramp section is preferably configured in such a manner that a cargo item which is travelling towards the latch device substantially along the longitudinal direction will activate the releasing device.
The latch device can have at least two releasing devices which are arranged on either side of the sliding guide carriage. In this respect, the direction from which the cargo item travels towards the sliding guide carriage is irrelevant for triggering of the releasing device as long as the direction of approach runs substantially perpendicular to the transverse direction of the latch device. A releasing device for releasing the sliding guide carriage can be located on each side of the sliding guide carriage.
The sliding guide carriage, the first and the second releasing device may be arranged substantially in a line running along the longitudinal direction.
It is conceivable for a mechanical coupling to exist between the releasing device and the sliding guide carriage. In this case, when the releasing device is pivoted out of the blocking position into the releasing position, it is possible for the sliding guide carriage to pivot automatically out of the restraining position into the inoperative position against the force of a lifting spring. On the other hand, the sliding guide carriage may have at least one sliding guide carriage ramp section which is arranged and configured in such a way that a cargo item approaching longitudinally will pivot the released sliding guide carriage out of the restraining position into the inoperative position. In this respect, a cargo item approaching longitudinally first releases the sliding guide carriage (triggering of the releasing device) and then, by means of the sliding guide carriage ramp section, pushes the sliding guide carriage out of the restraining position into the inoperative position.
The latch device preferably has two sliding guide carriage ramp sections, which are each arranged on either side of the sliding guide carriage such that the sliding guide carriage can be approached from both sides.
The bearing may have a slotted guide system and/or a plurality of rotary joints which are used to guide the sliding guide carriage out of the restraining position into the inoperative position. The sliding guide carriage preferably executes a translatory movement on moving out of the restraining position into the inoperative position. Provided that this translatory movement is implemented by means of rotary joints, the sliding guide carriage can be folded down like a parallelogram. This special configuration of the bearing has the advantage that jamming of the sliding guide carriage is prevented when switching between the restraining position and the inoperative position. Thus the sliding guide carriage may have locking lugs or similar restraining devices which are suitable for engaging in the cargo items in such a manner that said cargo items are also secured horizontally. These restraining devices can easily jam on the cargo item during rotational movements.
As already explained, the sliding guide carriage may have locking lugs which protrude transversally in order to engage in the cargo items. The sliding guide carriage preferably comprises a cross member and a longitudinal member for forming a T-section. Ultimately, the sliding guide carriage may be relatively flat such that the cargo items are guaranteed to be well secured. In addition, the flat design of the sliding guide carriage ensures the prevention of breakdowns due to incorrect operation. The latch device can also be used as a traversable guide if no cross member is provided.
The releasing device may comprise extensions which accommodate the releasing device ramp sections. The extensions may be arranged and/or aligned along the longitudinal direction of the latch device.
These extensions are preferably narrow in width, in particular less than 3 cm, in particular less than 2 cm.
The narrow width of the extension has the advantage that unintentional unlatching is eliminated. That is to say, a cargo item approaching transversally cannot activate the releasing device. The extension preferably has a lateral surface which ultimately extends parallel to the sliding guide carriage such that cargo items approaching transversally cannot activate the releasing device.
The at least one extension may have a width that is narrower than the width of the sliding guide carriage's cross member. For example, the width of the extension may be narrower than half the width of the cross member.
The latch device may have at least one spring assembly which preloads the sliding guide carriage in the restraining location/restraining position. In this respect, it is conceivable that the move out of the inoperative position into the restraining position is more or less automatic. Furthermore, a spring assembly which preloads the releasing device in the blocking position can also be provided. Here too, it is conceivable that the releasing device is automatically pivoted out of the releasing position into the blocking position by means of the spring assembly.
A blocking mechanism which renders it possible to lock the restraining carriage in the inoperative position may be provided. If the spring assemblies referred to above are present and the sliding guide carriage is in the inoperative position, the carriage can pivot automatically into the restraining position after triggering of the blocking mechanism and can be locked there by means of the releasing device.
The latch device may comprise a latch plate for fastening the latch device to the cargo loading deck and/or a profile rail.
The latch device according to the invention is preferably mounted in a profile rail.
The object referred to at the outset can moreover be achieved by a cargo loading deck comprising at least one latch device such as has been described previously.
The at least one latch device can be arranged centrally on the cargo loading deck to form at least one first cargo conveying path and at least one second cargo conveying path. The cargo loading deck is preferably configured in such a manner that a plurality of cargo conveying paths differing in their widths can be provided depending on the cargo loading deck's configuration. For example, a cargo conveying path approx. 125 inches wide can be divided by means of the latch device according to the invention into two cargo conveying paths approx. 62 inches wide such that cargo items with a width of 125 inches or 62 inches can be loaded depending on the configuration. In a different arrangement, a wider cargo conveying path could be divided, for example, into three or four tracks.
The invention is described below with reference to several embodiment examples which will be explained in more detail with reference to several drawings.